1. Field of the Invention
The invention relates to a portable navigational aid device for sailboats and like vessels for quickly determining which of two vessels which are crossing one another's courses should give the right-of-way to the other according to local rules of navigation.
2. Description of the Prior Art
The number of pleasure sailors has been increasing substantially during the past decade. Many of the persons piloting pleasure craft are only dimly and imprecisely aware of the various rules of the road as applied to boating. Therefore, in crowded waterways when decisions of right-of-way must be made very rapidly, considerations of tacking, wind velocity, wave conditions, etc. also occupy the mind of the person piloting the boat.
For sailing boats the rules of the road are rather complex, taking into account the wind direction with respect to each of the meeting vessels, their location with respect to one another and which boat is leeward of the other and the directions of their respective courses with respect to the wind and to one another. To determine the complex rules of the road, in addition to handling the exigencies of a boat, often results in errors which give rise to potentially dangerous accident situations.
In Swedish Pat. No. 1098 which deals with the study of the international rules of the road concerning ships, there is described a device called a navigation capstan. This device is large and unwieldy, being usable only by captains of large vessels, and is not meant to be used by persons sailing small pleasure craft. Nor does it provide an inexpensive and quick answer for the question as to which of the two meeting vessels has the right-of-way according to the local rules for sailboats.